Effect of the use of dexmedetomidine as an adjuvant in peribulbar anesthesia in patients presented for vitreoretinal surgeries

Efficacy of adjuvants in ophthalmic regional anesthesia: A systematic review and network meta-analysis

PURPOSE

This network meta-analysis aims to determine the differences between adjuvants that are used in combination with local anesthetics for ophthalmic regional anesthesia.

DESIGN

Systematic review and network meta-analysis METHODS: A systematic literature search for randomized controlled trials, comparing the impact of adjuvants in ophthalmic regional anesthesia, in Embase, CENTRAL, MEDLINE and Web of Science was performed. Risk of bias was evaluated using the Cochrane risk of bias tool. Frequentist network meta-analysis was performed using a random effects model with saline as the comparator. Primary endpoints were the onset and the duration of sensory block and globe akinesia, as well as the duration of analgesia. Summary measure was the ratio of means (ROM). Secondary endpoints were the rates of side effects and adverse events.

RESULTS

39 trials were identified as eligible for network meta-analysis, including 3046 patients. 17 adjuvants were compared in the most extensive network (onset of globe akinesia). The addition of fentanyl (F), clonidine (C) or dexmedetomidine (D) showed the best overall results. Onset of sensory block: F 0.58 [CI 0.47-0.72], C 0.75 [0.63-0.88], D 0.71 [0.61-0.84], onset of globe akinesia: F 0.71 [0.61-0.82], C 0.70 [0.61-0.82], D 0.81 [0.71-0.92], duration of sensory block: F 1.20 [1.14-1.26], C 1.22 [1.18-1.27], D 1.44 [1.34-1.55], duration of globe akinesia: F 1.38 [1.22-1.57], C 1.45 [1.26-1.67], D 1.41 [1.24-1.59], duration analgesia: F 1.46 [1.33-1.60], C 1.78 [1.63-1.96], D 1.41 [1.28-1.56].

CONCLUSION

The addition of fentanyl, clonidine or dexmedetomidine showed beneficial effects regarding onset and duration of sensory block and globe akinesia.

Effect of Dexmedetomidine in Sub-Tenon's Block on Emergence Agitation in Pediatric Strabismus Surgery under Sevoflurane Anesthesia

Background

Numerous unfavorable complications may occur with strabismus surgery as emergency agitation (EA), oculocardiac reflex (OCR), postoperative pain, and postoperative nausea and vomiting (PONV).

Aims

This study was designed to evaluate the dexmedetomidine effect in sub-Tenon's block on EA in strabismus surgery in the pediatric population under sevoflurane anesthesia.

Design

This was a prospective randomized double-blind clinical trial.

Patients and Methods

Eighty American Society of Anesthesiologists (ASA) Physical Status Class I and II pediatric patients, in an age group ranging from 2 to 8 years of either sex, had strabismus surgery under sevoflurane anesthesia using laryngeal mask airway. Patients were divided randomly into two groups (each = 40). Sub-Tenon's block is performed in the operated eye with 0.5% bupivacaine (0.08 mL.kg-1) alone in Group B (bupivacaine group), and with 0.5% bupivacaine (0.08 mL.kg-1) and dexmedetomidine (0.5 μg.kg-1) in Group D (dexmedetomidine group). Hemodynamics were monitored, and OCR was recorded. Furthermore, postoperative EA (Pediatric Anesthesia Emergence Delirium and Cravero Scales), pain (Face, Legs, Activity, Cry, and Consolability), and incidence of PONV were recorded as well.

Statistical Analysis

A prospective analysis of the collected data was performed using the SPSS program for Windows (version 26).

Results

The dexmedetomidine group exhibited a lower EA incidence, pain, and PONV as compared to the bupivacaine group. No statistically significant differences regarding hemodynamics, OCR, or emergence time were found between both the groups.

Conclusion

The addition of dexmedetomidine to bupivacaine in sub-Tenon's block can alleviate postoperative EA and nausea and vomiting with better pain management and hemodynamic stability in pediatric strabismus surgery under sevoflurane anesthesia.

Efficacy of ropivacaine versus bupivacaine in preventing peribulbar block failure: A meta-analysis

PURPOSE

Peribulbar block is considered a standard of care in ophthalmological practice due to its easy execution and minor complications. There is a paucity of studies confirming efficacy between ropivacaine and bupivacaine for this specific technique. We evaluated the efficacy of ropivacaine or bupivacaine in preventing total or partial peribulbar block failure in ophthalmic surgeries.

METHODS

Meta-analysis of randomized clinical trials, comparing patients submitted to ophthalmic surgeries under peribulbar anesthesia with ropivacaine and bupivacaine. We searched in different databases for articles published until March, 2018. Data on patients, anesthesia, procedures and akinesia were tabulated. After calculating the chi-square of heterogeneity, we adopted a random-effects model with DerSimonian-Laird test, as well as an odds ratio and a 95% confidence interval.

RESULTS

From the 310 articles identified, 21 studies were selected. The use of ropivacaine was considered a protective factor for ocular akinesia failure in peribulbar block when compared to bupivacaine (OR = 0.53, 95% CI = 0.35-0.81 and p value = 0.003).

CONCLUSIONS

In ophthalmic surgeries, ropivacaine in peribulbar anesthesia is associated with lower rate of block failure when compared to bupivacaine.

Dexmedetomidine during suprazygomatic maxillary nerve block for pediatric cleft palate repair, randomized double-blind controlled study

Background

For children with cleft palates, surgeries at a young age are necessary to reduce feeding or phonation difficulties and reduce complications, especially respiratory tract infections and frequent sinusitis. We hypothesized that dexmedetomidine might prolong the postoperative analgesic duration when added to bupivacaine during nerve blocks.

Methods

Eighty patients of 1-5 years old were arbitrarily assigned to two equal groups (forty patients each) to receive bilateral suprazygomatic maxillary nerve blocks. Group A received bilateral 0.2 mL/kg bupivacaine (0.125%; maximum volume 4 mL/side). Group B received bilateral 0.2 mL/kg bupivacaine (0.125%) + 0.5 µg/kg dexmedetomidine (maximum volume 4 mL/side).

Results

The modified children's hospital of Eastern Ontario pain scale score was significantly lower in group B children after 8 hours of follow-up postoperatively (P < 0.001). Mean values of heart rate and blood pressure were significantly different between the groups, with lower mean values in group B (P < 0.001). Median time to the first analgesic demand in group A children was 10 hours (range 8-12 hr), and no patients needed analgesia in group B. The sedation score assessment was higher in children given dexmedetomidine (P = 0.03) during the first postoperative 30 minutes. Better parent satisfaction scores (5-point Likert scale) were recorded in group B and without serious adverse effects.

Conclusions

Addition of dexmedetomidine 0.5 µg/kg to bupivacaine 0.125% has accentuated the analgesic efficacy of bilateral suprazygomatic maxillary nerve block in children undergoing primary cleft palate repair with less postoperative supplemental analgesia or untoward effects.